Blood oxygenator provided with rocker means



Oct. 19, 1965 BLOOD OXYGENATOR PROVIDED WITH ROCKER MEANS Filed Nov. 15, 1962 W. R. KORESKI illla.

5 Sheets-Sheet 1 INVENTOR.

W. R. KORESKI BLOOD OXYGENATOR PROVIDED WITH ROCKER MEANS 3 Sheets-Sheet 2 94x74! 4 4. fun.:

INVENTOR.

Oct. 19, 1965 Filed Nov. 15, 1962 Oct. 19, 1965 w. R. KoREsKl 3,212,499

BLOOD OXYGENATOR PROVIDED WITH ROCKER MEANS 3 Sheets-Sheet 3 Filed NOV. 15, 1962 INVENTOR. WILLIAM R. KRESKI United States Patent O 3,212,499 BLOOD OXYGENATOR PROVIDED WITH ROCKER MEANS William R. Koreski, 5836 57th NE., Seattle 5, Wash. Filed Nov. 13, 1962, Ser. No. 236,994 7 Claims. (Cl. 12S-214) This invention relates to the oxygenation of blood, and 'for its general object aims .to provide an eicient bloodoxygenating machine and method of the type which simulates the mammalian lung, namely a machine and method passing the oxygen through a semi-permeable membrane and hence isolating the blood against direct interface with gaseous oxygen.

The oxygenation of blood is important to many fields of medicine 'but is vital for -open-heart surgery, where surgical treatment inside ,a patients hear-t demands that provision be made to artificially carry out the functions of the heart during .the period in which the heart is being operated upon. Heart-lung machines, by which ter-m artificial mediums are customarily known, must not only take over the hearts pumping function, but must also take over the llungs oxygenating function. This is because the intimate anatomical and physiological relationship between a persons heart and lungs does not allow the heart to -simply Ibe by-passed during the operation. The two must be considered as a unit. The heart being a simple str-aight- -forward mechanical pump, it has been no great challenge to devise pumps that would circulate blood through the body in a relatively atraumatic manner and under suitable circumstances. The great problem has been the creation of oxygenators which would perform their function of .an artificial lung with complete freedom from any -adverse side effect.

Oxygenating equipment as presently known can be said to carry out it-s intended function by one of three techniques.

One is by bubbling oxygen through the blood itself, producing a saturated solution which allows the hemoglobin -in the red cell to 'be converted to -oxyhemoglobin by taking up oxygen from the solution. While this is an extremely efficient method for converting the hemoglobin content of the red cell, it is recognized that blood is damaged by bubbling of oxygen therein and it is of particular interest that the direct interface between the gaseous oxygen and the blood itself leads to profound changes in the blood proteins.

The second technique produces .a blood film either on a screen, sharp edges of moving discs, or a fiat surface, and exposes this film to high concentrations of oxygen. This, likewise, efficiently converts hemoglobin into oxyhemoglobin, and thus substitutes for the function of the lung, but in consequence of the interface which is present between the oxygen and the blood much the same distion through the membnane while carbon dioxide present in the blood passes in the other dir-ection through the membrane. All experimental evidence appears to establish that an artificial m-achine incorporating a functioning lcounterpant of the pulmonary air sac provides the most desirable oxygenation system but problems have arisen in prior efforts to employ same. Until quite recently one obstacle to efficient use of this technique had been an in- ICC -ability to find a suitable semi-permeable membrane. Many substances can qualify as 'being semi-permeable, notably cellophane, Teflon, polypropylene, silicone rubber, Saran, and some formulas of vinyls. Teion (tetraflorethylene), a product of the Du Pont Company, in the thin form in which it can now be produced (/s to 1/2 mil), is found to perform very efficiently 'both in transferring oxygen to the lblood and also in transferring carbon dioxide from the blood. The existing oxygenators which presently use this material ,are objectionable on the count of requiring membranes of a thicker fabrication. While there have been unsuccessful efforts to employ gravity in flowing blood through a potential membrane space, all of the heretofore Aaccepted membrane-type oxygenators have found it necessary to pump the blood under considerable pressure through the membrane space. Only the thicker membranes avoid tearing of lthe membrane itself under this pressure force.

The system of the present invention drains the blood lby gravity fr-om the patient into a reservoir, and from the reservoir leads the blood by gravity through an envelope composed of thin Teiion. The relatively thick blood surface which is produced within the envelope would, theoretically, be unsuitably distributed for good oxygenation. We find that we can eectively distribute the blood over the membnane surface and achieve excellent oxygenation by supporting the envelope upon a rocking screen.

The present invention consists in the new method of oxygenating blood and in the construction, 'adaptation and combination of the par-ts of a machine for practicing said method, hereinafter described .and claimed.

In the accompanying drawings:

FIGURE 1 is a top plan view, with parts broken away, illustrating a machine constructed to embody preferred teachings of the present invention.

FIG. 2 is a side elevational view thereof.

FIG. 3 is .a fragmentary longitudinal vertical sectional View drawn to an enlarged scale on lline 3 3 of FIG. 1.

FIG. 4 is a fragmentary longitudinal vertical sectional view drawn to a yet larger scale on line 44 of FIG. 1.

FIG. 5 is a fragmentary transverse vertical sectional View on line 5-5 of FIG. 2, the view being somewhat schematic in that the rocker-mounted screens are shown in full lines and the cabinet in which these screens are housed is shown in phantom. The scale employed is somewhat larger than that of FIG. 3.

FIG. 6 is a transverse vertical sectional view drawn to an enlarged scale on line 6-6 of FIG. 1 detailing one of dthe oxygenating envelopes and its supporting screen; an

FIG. 7 is a fragmentary longitudinal vertical sectional view detailing a screen configuration modified from that which is shown in FIG. 4.

Referring to said drawings, the cabinetror chest as it will be hereinafter termed, is designated by the numeral 10. As here illustrated, the chest is rigidly supported upon a dolly-like platform 11 by corner posts 12. The dolly wheels 16 permit the machine to be easily moved from one to another operating location. The chest is airtight, With a close-fitting removable top 13, and at the bottom and top, respectively, provides means 14 and 15 for delivering oxygen to the interior and for exhausting CO2-laden air from the interior. A check-valve is provided in the outlet. The oxygen is desirably introduced to the chest at no higher pressure than two atmospheres in order to create no inhibition to passage of carbon dioxide through the walls of the Teflon envelopes, hereinafter to be described.

A plurality, four being shown, of frames 20 are received in the interior of the chest for rocker motion about axes located on the longitudinal median line of the chest and sloping from the horizontal downwardly in a moderate degree toward the front. Bearings 21 and 22 which provide the rocker journals for said frames are carried by the end walls 23 and 24 of the chest and receive a set of hollow stem pieces, as 25 and 26, which are rigidly secured to the frames at the two ends thereof. The front stems 26, one for each frame, project beyond the related bearings 22 and each has the hub end of a respective lever 27 fixed to such protruding end. The arms of these several levers extend laterally from the hubs, one parallel to another, and have their free ends attached by universal connections to a vertical bar 30. The bar connects in turn, by a pitman 31, with a crank-wheel 32 driven from an electric motor 28, the drive being passed to the crank-wheel by reduction gearing contained in a gearbox 29.

Each of the frames outlines an opening of rectangular plan configuration, and has a screen 34 stretched across the opening to produce a foraminous floor. The Teflon envelopes 35 of the present invention rest upon the screens, being provided at both ends with hollow necks, as 36 and 37. These necks fit the hollow centers of the stems 25 or 26, as the case may be. Necks 36 and 37 respectively serve an ingress and an egress function. As we have elected to here illustrate the same the outer ends of the ingress necks 36 protrude beyond the back wall 23. Each is clamped to the outlet end of a respective feed tube 38 draining by gravity from a reservoir 40 arranged to receive venous blood from a patient through a gravity-drain tube 41. The egress necks 37 of the envelopes are shown as being tted in the inner end of a nipple 42 received in the hollow center of the related front stem 26. The outer ends of these several stems have a journal t in a receptacle 44 which is iixedly supported by the chest and leads to the suction side of a pump (not shown) housed in a casing 43. The pump returns the oxygenated blood to the patient by an arterial tube 45.

In the embodiment of FIG. 7 it will be seen that the frame 20 is so formed that the screen 34 presents a dip 50 at its head end. This dip extends transversely the full width of the screen. The envelope 35 conforms to the shape of the screen and a sump-like pocket 51 is thus presented to the introduced blood, its purpose being to spread the blood laterally Within the envelope. The embodiment of FIG. 4 is designedto accomplish a similar end by the expedient of choking the outlet from the envelope.

While not illustrated, I nd that a desirable method of producing the present machine is to position the rocker axes of the several rocker-mounted frames parallel with the bottom wall of the cabinet, and give the cabinet a tilt from the horizontal by supporting the same upon front legs which are shorter than the rear legs. The rocker axes should have a slope desirably between and 7 from the horizontal. In this alternative construction the drive motor is so mounted below the cabinet that its rotary axis parallels the rocker axes.

Dimensionally considered, and by way of example, envelopes of 46" length, 12" width, and 1A mil thickness, rocking at cycles per minute through approximately 60 of travel, effectively oxygenates a blood ow, per envelope, of 500 cc. per minute. The cycles per minute may be varied to cause the blood to travel more or less distance end to end and thus permit an increase or decrease in the surface area of the membrane.

It is believed that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiments. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

What I claim is:

1. A blood oxygenator comprising a chest having widely separated oxygen inlet and outlet openings to and from the interior, a foraminous generally horizontal tray journal-mounted for rocker motion within the chest, an envelope supported upon the tray composed of a semipermeable material, means for passing blood which is to be oxygenated through the envelope in a general direction longitudinal to the rocker axis, means for rocking the tray about said rocker axis, and means for continually introducing oxygen through 4the inlet opening to the interior of the chest to displace through the outlet opening a corresponding volume of the contained gaseous medium to which carbon dioxide has been transferred from the blood.

2. The blood oxygenator of claim 1 in which the envelope is composed of tetrallorethylene having a thickness no less than 1/10 mil nor greater than 1/2 mil.

3. The blood oxygenator of claim 1 having a plurality of said trays, and a respective envelope for each of the plural trays.

4. The blood oxygenator of claim 1 characterized in that the inlet opening is located at the bottom and the outlet opening at the top of the chest.

5. A blood oxygenator comprising a chest having inlet and outlet openings to and from the interior, a tray having a foraminous floor and mounted within the chest for rocker motion about the trays longitudinal median line as an axis, an envelope of semi-permeable material supported upon said floor of the tray for movement in concert with the tray, means for supplying `venous blood drawn from a patent into one end of the envelope and taking the blood from the other end for return as arterial blood to the patient, means for rocking said tray, and means for continually introducing oxygen through the inlet opening so as to flood the interior of the chest while dissipating through the outlet opening a corresponding volume of the contained gaseous medium to which carbon dioxide has been transferred from the blood.

6. A blood oxygenator according to claim 5 in which the tray occupies a plane sloping downwardly from the end of the supported envelope into which the blood is supplied.

7. The blood oxygenator of claim 5 in which the blood has a gravity flow between said two ends of the envelope, means being provided at the head end of the envelope causing the entering blood to film out Within the envelope.

References Cited by the Examiner UNITED STATES PATENTS 2,552,188 5/51 Krause et al. 259-75 2,675,349 4/54 Sarnoif et al 210-321 2,757,375 7/56 Rieutord et al. 128-214 X 2,845,929 8/58 Strumia 128-214 X 2,982,286 5/61 Welch 128-276 3,026,871 3/62 Thomas 128-214 OTHER REFERENCES Gentsch et al.: Experimental and Clinical Use of a Membrane Oxygenator, from Surgery, vol. 47, No. 2, February 1960, 1284214 Lit., pp. 301-313.

Weale: Pressurized Oxygen for Total Body Perfusion, Lancet, September 9, 1961, pp. 570-3.

RICHARD A. GAUDET, Primary Examiner.

JORDAN FRANKLIN, Examiner. 

1. A BLOOD OXYGENATOR COMPRISING A CHEST HAVING WIDELY SEPARATED OXYGEN INLET AND OUTLET OPENINGS TO AND FROM THE INTERIOR, A FORAMINOUS GENERALLY HORIZONTAL TRAV JOURNAL-MOUNTED FOR ROCKER MOTION WITHIN THE CHEST, AN ENVELOPE SUPPORTED UPON THE TRAY COMPOSED OF A SEMIPERMEABLE MATERIAL, MEANS FOR PASSING BLOOD WHICH IS TO BE OXYGENATED THROUGH THE ENVELOPE IN A GENERAL DIRECTION LONGITUDINAL TO THE ROCKER AXIS, MEANS FOR ROCKING THE TRAY ABOUT SAID ROCKER AXIS, AND MEANS FOR CONTINUALLY 